Lightning-arrester



(No Model.) 2 SheetsSheet l.

E. G. MILLER. LIGHTNING ARRESTER.

No. 472,135. Patented Apr. 5, 1892.

ATTORNEYS (No Model.) 2 SheetsSheet 2- E. G. MILLER.

LIGHTNING ARRESTER.

No. 472,135. Patented Apr. 5, 1892.

1mm Hll O WIN/8858: 1 IIVVENTOR W/M. -eak w4 JQW 1% ATIORNEYS UNITED STATES PATENT OFFICE.

EDIVARD G. MILLER, OF \VILKINSBURG, PENNSYLVANIA.

LIGHTNING-ARRESTER.

SPECIFICATION forming part of Letters Patent No. 472,135, dated April 5, 1892. Application filed August 27,1890. Serial No. 363,163. (No modell) To all whom, it may concern.-

Be it known that I, EDWARD G. MILLER, of VVilkinsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and Improved Lightning-Arrester for Electric-Light Circuits, of which the following is a specification, reference being had to the annexed drawings, forming a part thereof, in which Figure 1 is a side sectional elevation of my improved lightning-arrester. Fig. 2 is a detail View of one of the carbon-holders, and Fig. 3 is a diagrammatic view showing the circuits.

Similar letters of reference indicate corre-- sponding parts in all the views.

The object of my invention is to construct a lightning arrester for dynamo circuits which will convey the charge to the ground, thus preventing it from reaching the dynamo; also, to extinguish any are that might be formed by the passage of the lightning.

My invention consists in a helix provided with a mercury-switch at the bottom, and furnished with a movable core or armature for displacing the mercury.

It also consists in the combination, with the helix and the circuits, of a series of carbon blocks arranged in a line with narrow airspaces between them, all as will be hereinafter more fully described.

The helix A is provided with a tubular core B, which projects below the lower end of the helix and is closed at its lower end by the axially-bored plug 0, which serves to reduce the retaining capacity of the lower end of the tubular core B. In the tube is placed an armature D, formed of a bundle of iron wires having spiral wrappings a, the bundle being inclosed at its lower end in an insulating-tube b and furnished with collars c, which loosely fit the tubular core B. In diametrically-opposite sides of the tubular core B are inserted the screws d d, which clamp the ends of the conductors e e, and in the tube 1) is placed a body of mercury E.

The upper end of the helix A is furnished with a cap f, which prevents the armature D from being thrown out of the helix, and also excludes dust and moisture. To the base F,

which supports the helix A, are attached the carbon-clamps G, G, and G The construction of these clamps is shown in Fig. 2. Each clamp consists of an angled plate g, provided with a jaw h, which extends upwardly parallel with the base-board, a carbon block e being held in the jaw by the thumb-screwj. A wire it extends from the clamp G to the conductor to be protected. The clamp G is connected with one terminal of the helix A. The remaining terminal is connected with the clamp G and the said clamp is connected by the wire 6 with the screw (1. The wire a, which is connected with the screw cl, is attached to the clamp Z, which receives the ground-wire.

One such arrester is to be attached to each line, as showh in Fig. 3. The carbon platesz 7." 2 held by the clamps G G G are arranged near, but not in contact with, each other, the carbons i 2" being separated a little more than the carbons 4." 2'

\Vhen the current is working normally, the parts of the arrester remain in the condition shown in Fig. 1; but when either branch of the line is struck by lightning the charge escapes by way of the wire 7i) and carbon plates 2 2 The lightning, leaping from the plate 1' to the plate 1', either passes through the clamp G and helix A to the clamp G thence through the wire F and through the mercury in the lower part of the core 13 to the ground-pin, or it may leap the space between the plates '5 e and then pass through the wire F, thence to the ground, as before.

If an arc is established between the carbon plates and the dynamo findsacircuit through the arrester and the ground the helix A becomes energized and draws up the armature D, thus allowing the mercury to recede from the screws cl d, breaking the ground connection and returning the circuit to its normal condition.

Having thus described my invention, I claim as new and desire to secure by Letters Patent- 1. In a lightning-arrester for dynamo-circuits, the combination, with the plates 2' t" 2' and clamps G G G of the helix A, connected to the plates G G the armature D, the core B, provided with the mercury-changer, and the plate G connected with the ground throughout, substantially as specified.

2. In a lightning-arrester for dynamo-circuits, the combination, with the helix A, procontaining the body of mercury E, the contact-screws d d, entering the tubular core B, the ground -wires 6 e, connectedv with the clamp G and screws d d, and the armature D, furnished with the insulating-covering b, and the guidingcollars c, substantially as specified. 4

EDWARD G. MILLER.

Witnesses: G. P. SHANE,

J. A. E. HOEVELER. 

